I know I'm dredging up an old post but we have the same issue with our HP LaserJet pro 400 series printers. White space is removed from the middle and the bottom text is moved up.
We use A4 paper size and PCL6 drives (not the universal driver).
I did not see a reply from the original poster after the two replies so I added my comments to bump the post and give it some attention.
Thanks in advance for you help.